topic Re: structure with offset rim in Civil 3D Forum

structure with offset rim

Joe-Bouza — Wed, 29 Apr 2026 12:20:14 GMT

Can a structure be created like this block? any tips? my part builder skills are not so great.

The issue: I use an OOTB concentric structure and the block for plan. The insertion point is the Rim. this reads the correct surface elevation but the pipes have to be dragged as shown. no terrible but the worse part is the length is pipe is wrong {inside edge to inside edge}, The model is centered at the block insertion.

Re: structure with offset rim

chriscowgill7373 — Wed, 29 Apr 2026 12:39:38 GMT

I dont think there is a way to get an offset elevation location that is separate from the insertion of the structure. You might be able to use IPE instead of part builder to add additional connection points, but, I dont have any experience with that. I would think based on your image, eccentric would be the better default part to use over concentric, as your surface is shifted off from your main structure. Perhaps rotating it would allow it to work, but I dont know, I've not really ever used eccentric before. We've always just used slab top so it would show as a rectangle in profile view, and figured the contractor would figure out what parts and pieces to get to achieve the final end structure rims and inverts.

Re: structure with offset rim

Joe-Bouza — Wed, 29 Apr 2026 21:46:30 GMT

Yeah, we did all that. even the eccentric is wonky for the 12 & 10 foot dia structure..

yo are correct rotating in line works, but the insert is rotated specifically to pickup a desired elevation

Re: structure with offset rim

MikeEvansUK — Thu, 30 Apr 2026 13:56:14 GMT

Hi Joe, this can be done.

You retain the existing centrepoint and zero point in the model, create a new Workplane at the level you want and add a referance point from the top plane.
Add annother point anywhere then add controlling dims X,Y to tell it an offset from the master.
The dims can be set via values or a calc if needed, could be helpful to add a new context to allow this to be passed between mutiple parts and read in Civil3d.
All geometry is then related to this new offset point.
Pipework retains the connection as per the centroid.

I don't use IPE as do not have access to inventor so do everything in PE. Just wish they'd fix PE's revolve functions.

Mike

Re: structure with offset rim

navya_gelli — Thu, 07 May 2026 11:19:48 GMT

Hi @Joe-Bouza,

Did the info from @MikeEvansUK help answer your question?

If it did, it’d be great if you could click the "Accept Solution" button so others can easily find it too.

If you’re still needing more help, feel free to share an update here. The community will be happy to jump in with any next steps to help you get where you need to be.

Best,

Navya | Community Manager

Re: structure with offset rim

Joe-Bouza — Fri, 08 May 2026 21:33:12 GMT

@MikeEvansUK

Wow Mike, pardon my delay. I missed the notification. This definitely looks like what we need to do. A little beyond my current Part builder knowledge/ ability. I will accept and try my hadn at it.

Do you know of any vids or help docs that may helpful?

Re: structure with offset rim

Joe-Bouza — Fri, 08 May 2026 21:38:50 GMT

@navya_gelli , @chriscowgill7373 , @MikeEvansUK

I would put this in as an Idea but this should really be an OOTB choice for parts. Most real world parts are like that.

Thanks again

Re: structure with offset rim

Joe-Bouza — Fri, 08 May 2026 21:39:15 GMT

yes thank you.